This invention relates to a novel spring wire contact assembly, and more specifically relates to a novel spring wire contact assembly which has particular use in connection with an arc spinner type of circuit interrupter.
Arc spinner circuit interrupters are well known and are shown, for example, in U.S. Pat. Nos. 4,052,576 and 4,079,219. The movable contact structure used in these devices is a cylindrical contact finger assembly made from a single piece of tubular material which has been machined and segmented by mill cutting. Such contact structures are also shown in U.S. Pat. No. 4,142,560. This main contact assembly then telescopes over a cooperating contact asembly and contact pressure is obtained by the forces required to flex the individual fingers outwardly during the contact engagement operation. A one-piece machined cylinder for a movable contact is expensive and numerous problems arise when using the resulting contact structure.
It is known that the single machined cylinder for a movable contact structure can be replaced by a cluster of wire fingers, as shown in U.S. Pat. No. 4,072,392, entitled "Spring Wire Formed Tulip Contact", in the names of McConnell and Kucharski and assigned to the assignee of the present invention.
However, the use of the spring wire fingers shown in U.S. Pat. No. 4,072,392 does not lend itself directly to use with arc spinner interrupters of the type shown in U.S. Pat. No. 4,052,576 which require a main contact area as well as a current transfer region connected to the main movable contact but removed from the main contact area. Moreover, the assembly of the spring wire element of U.S. Pat. No. 4,072,392 is complex because it requires the handling of many individual elements, while the use of a single, continuous bent wire produces serious fabrication problems.